The present invention relates generally to methods, apparatus, and a kit for installing window film structures in combination with window film assemblies or the like. More particularly, it relates to methods, apparatus, and a kit for easily and reliably installing window film structures in a manner for avoiding formation of permanent film flaws therein diminishing their optical properties, while at the same time may enhance thermal insulation for associated window assemblies.
Window films are generally transparent plastic and/or metallized laminates applied as a thin layer to transparent panels, such as glass windows. Window films are available in many different compositions for bringing about varying effects on the optical and mechanical properties of the underlying transparent panels. Window films can reduce energy costs by minimizing the amount of heat entering a building through sunlight, thereby decreasing the amount of energy needed to cool the building. Window films also act as a filter for reflecting most ultraviolet and infrared wavelengths while allowing passage of visible light. This can result in substantial reductions in cooling costs. As noted, such films reduce the amount of ultraviolet entering a window, and are also often applied to reduce fading of the contents of a room. Other kinds of thin window films include security films applied to prevent glass from shattering, as well privacy films for controlling the visible light transmitted for effecting privacy purposes.
It will be appreciated that several factors are considered in selecting the correct film to be installed. Such factors include visible light transmission, properties of solar energy to be reflected, and decorative considerations, such as distortion free viewing following installation.
Because window films are usually installed by applying them to either or both surfaces of flat finished glass, the resulting laminates are less costly than buying chemically altered specialty glass for bringing about the same desired solutions. Because window films provide energy savings and help protect furnishings among other advantages, they are generally considered to be an investment that helps pay for itself. As such, they have gained widespread commercial acceptance.
Unless the window films are properly applied to windows, there is a chance that they will crease and fold, during cutting and installation due to their inherent highly flexible nature. Due to the inherent mechanical and chemical properties of these films, their installation can be tedious and subject to several shortcomings particularly in a do-it-yourself context. Generally, window films are thin and may be difficult to handle, especially if large window panels are to be laminated. For example, window films are relatively thin, such as up to 4 mils. These thin films have a tendency to fold upon themselves. Measuring and cutting thin films to the correct size before they are directly applied is particularly difficult, especially if irregular window shapes are involved and installation is performed by non-professionals, such as a do-it-yourself installer. Additionally, most window films are covered by a release sheet that must be removed before application of the film on the window. However, there is a strong tendency for the thin adhesive covered film surface to permanently wrinkle, crumple, or crease as the release sheet is manually removed. Accordingly, these film surfaces may stick to themselves even before the release sheet is completely removed. Creasing, wrinkling, etc. may cause permanent film flaws eventually that lead to discarding the films. Moreover, there is a chance that they will cause permanent flaws in the film which diminish their optical properties. Some of these window films include ultraviolet (UV) blocking materials that may in certain circumstance even damage the underlying window to which they are applied. As such, it is desired to avoid having the UV blocking film contact the window directly.
Also, such window film sheet structures are typically provided with an adhesive layer. The adhesive layer is exposed following removal of a low adhesion release liner and mounted to a window casement or the like. As noted, cutting and installing such thin films tends to be problematic due to their very flexible nature not to mention the adhesive layer sticking to itself in the process. As such, adhesives tend to further limit their uses, especially in do-it-yourself applications.
Attempts have been made to space transparent films from windows in order to improve the R-value associated with the windows. An R-value is a rating utilized to measure how well insulation can resist heat flow. The higher the R-value, the greater the insulating properties. However, while window films are beneficial they have not necessarily been successfully adapted for use in installation over transparent panels, such as windows. In part, this is due to the films being very thin, such as in the order of about 1 mil to about 4 mil. Typically, when applied to a frame for mounting the same, they cannot be kept planar over a frame opening. This is due primarily to their very flexible nature (i.e., they cannot sustain their dimensions). Accordingly, physical distortions of the films may arise and their optical properties are compromised. Because these films tend to be heat shrinkable, one typical approach for addressing their very flexible nature is to apply heat locally on the film. This is usually done by a hair dryer, heat gun, or other similar device. Heating causes the film to shrink over the frame opening, whereby it assumes a taught and generally planar orientation. As such, visual distortions thru the film are minimized and the appearance of the film over the window appears decorative. However, when heat is applied, it is usually done after the film has been applied to the frame and the film has reached room temperature of its operating environment. In some cases, heat is applied up to 24 hours after the film has been mounted on a frame. Clearly, this additional labor and time inhibit the ability for quickly and reliably mounting window film sheet structures to frames in many situations.
Also, direct application of the adhesive layers to window casements or the like inhibits reuse from heating season to heating season since the adhesive qualities tend to diminish through repeated usage. In addition, if window films are directly attached to windows, they are difficult to remove.
Thus, due to the number and complexity of steps involved in installing inherently very flexible film, along with the adhesive issues associated with installing thin window films, the prior approaches are generally considered time consuming, demanding, as well as potentially costly. These burdens are even more pronounced particularly in the do-it-yourself field, wherein a typical installer has very little experience handling these materials.
Without the foregoing issues being satisfied, the true potential of successfully applying and using window film sheet structures in a manner that: avoids optical distortions due to their very flexible and adhesive qualities causing permanent film flaws; and, promotes thermal insulation during repeated heating seasons may not be fully achieved, especially in a simple, reliable, less time consuming and less costly manner.